Necrotising otitis externa is an aggressive infection of the external ear, which extends to the surrounding bone and soft tissue. In recent years, there has been an apparent increase in the number of patients admitted to our hospital with this condition.

A retrospective review was conducted of all patients admitted to our hospital with necrotising otitis externa between July 2012 and June 2020.

Among 39 patients included, only 9 were diagnosed in the first four years, and 30 were diagnosed in the last four years. There were 27 males and 12 females, and the mean age was 78.7 years. There were six non-diabetic immunocompetent patients. Cranial nerve palsies developed in 50 per cent of the patients. Disease-related mortality was 7.7 per cent. A favourable outcome was recorded in 66.7 per cent of the patients.

Necrotising otitis externa is associated with high morbidity and mortality. The incidence of the disease is rising in our local geographical area.

In the light of current concerns regarding ciprofloxacin resistance and the changing face of malignant otitis externa, we reviewed cases of malignant otitis externa treated in our centre, in order both to evaluate the current epidemiology of the condition and to assess the status of drug resistance in our patient population.

Retrospective case review of all malignant otitis externa cases managed in a tertiary referral centre in the north-east of England between 2000 and 2009.

Forty-one patients were identified, but the required data were available for only 37 cases. Patients' ages ranged from 51 to 101 years (median, 81 years). Diabetes was present in 51 per cent of patients (19/37), facial nerve palsy in 40 per cent (15/37) and multiple cranial nerve palsy in 24 per cent (9/37). Pseudomonas aeruginosa was the most commonly isolated organism (54 per cent), sensitive to ciprofloxacin in all cases.

The incidence of cranial nerve palsy in our study was higher than in previous reports. The incidence of diabetes and Pseudomonas aeruginosa in our cohort was much lower than previously reported. The Pseudomonas aeruginosa strains isolated were all sensitive to ciprofloxacin, despite recent reports on emerging resistance.

Malignant otitis externa is a life-threatening infection of the skull base. Its presentation is not always typical.

We report three cases of malignant otitis externa which illustrate the diversity of its clinical manifestations and the difficulties in its diagnosis.

The perception of malignant otitis externa as an infection caused by Pseudomonas aeruginosa in diabetic patients is not always correct. The adoption of diagnostic criteria could be helpful in identifying atypical cases.